Process and apparatus for treating heavier hydrocarbons



NOV. 7, 1933. N H N D 1,934,004

PROCESS AND APPARATUS FOR TREATING HEAVIER HYDROCARBONS Filed Sept. 17, 1928 2 Sheets-Sheet l {Q xx} x D Q I W :m s W v m v Q h v Q a i Y Tm MN fir a x a Q L. 1 1w i Q m m H. W .m as a E \N E \k R N e \1 QM a a m {X 7 3 Nov. 7, 1933. N. H, RANSTEAD PROCESS AND APPARATUS FOR TREATING HEAVIER HYDROCARBONS Filed Sept. 1'7, 1928 2 Sheets-Sheet 2 fig E n n J L AW 5? m a o o o 0 5 EU av 8 Rn 11-5--mmyil w H Mwwmwm \Nmv w w Qr. 9% m a \m H l l l l MMHl l l l -F 1 I I H WIVH. H U I I Rn N mm km @S mm I n l l lnm WPH I u- I u. NW \w w .h NH

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Patented Nov. 7, 1933 IRQCESS AND APPARATUS FOR TREATING HEAVIER HYDROCARBONS Norman H. Ranstead, Whiting, Ind., assignor to Jenkins Petroleum Process Company, Chicago, 111., a, corporation of Wisconsin Application September 17, 1928 Serial No. 306,516

Claims. (Cl. 196-59) This invention relates to a process and apparatus for treating eavier hydrocarbons such as petroleum oils and particularly to improvements in a method and apparatus for securing the fullest 5 adv ntages of the apparatus and process described U. S. Patent 1,321,749 patented Nov. llth, 1919 l my copending application Ser. No. 286,895, d June 20, 1928, of which the present is a continuation in part.

In the practice of the process to which this invention relates the heavier oil is continuously charged into a still, a portion thereof is continuously vaporized and withdrawn, and a part of the still contents is rejected or discharged in a continuous or substantially continuous manner; all at a temperature and under a pressure best suited to obtain the desired objectives; theprocess being carried out in a still. comprising a heating bank oi tubes expanded into front and rear 20 transverse drums respectivel set under and connected to a superimposed longitudinal drum by means of suitable sluiceways, in one of which sluiceways is located a motor-driven propeller h serves to produce a constant circulation coincl ent with the other simultaneous functions.

Gther phases of the process include, besides the basic functions mentioned, the likewise continuous partial dephlegmation of the initially produced light vapors in their ascent through a loaffie tower, the escape therefrom at reduced pressure of the semi-fractionated desirable light oils and the return to the still at full pressure of be. e tower condensate together with fresh charging stock introduced at the top or" the bafiie tower and flowing downwardly therethrough in contracurrent to t. c ascending light oil vapors; charging stock being either a pure liquid hydrocarbon or an admixture of such hydrocarbon with a suitable adsorbent.

former operatinf conditions there exmarlr d tendency for the open inlet of neu ithdrawal line entering the front transverse drum to become clogged by solid material sue-.1 as carbon, causing either compl te or partial st of the withdrawal or" oil from the still e concentrates molecular weight i supe ..turated carbon content, variation in ercentage dispersion of suspended material out the liquid body within the still'and ral alteration of quality and quantity of the osirable light oils produced; the ultimate result being the shutting down of the still with its attendant costs of cleaning and indirect overhead charges for inactive time periods.

A primal object of this invention is to provide a method whereby the continuous or substantially continuous flow of oil having suspended therein objectionable polymerides from the main liquid body or bulk charge may be assured at all times.

Another object of the invention is to prevent excessive reduction of the bulk charge of the oil to the point of carbon supersaturation, and to provide a method for correcting abnormalities in 65. gravity and quantity of bulk still contents, by selectively introducing correctives in a plurality of finely divided streams immediately assimilated in the bulk circulation.

A further object of the invention is to prevent filtration of degraded oil through deposits adjacent to inlet of withdrawal line and to further inhibit such deposits, thus preventing an increase in the dispersion of solids in the still and a decrease of concentration of solids in the stream of oil flowing from the still.

A still further object of the invention is to force back into suspension in the liquid body of the still any material which may have been deposited at any point in the still, so that the continuous rejection of a portion of the liquid still contents will effect a coincident removal of a constant percentage of all solid matter.

Another object of the invention is to preclude undesirable concentrations of adsorptive deriva- 85. tives and their objectionable decomposition because of such concentration or because of being too long subjected to heat influx.

Further objects of the invention are the maintenance of a constant composition in the bulk of oil in the still and in the oil withdrawn therefrom and a constant percentage relation thereof to the amount of charging stock and introduced adsorbents.

A still further object of the invention is to provide a method for quickly cooling the entire liquid content of the still to any desired degree, by the selective introduction of cooling oil'in a plurality of finely divided streams, so that the maximum interchange of heat is effected, coincident with a progressively regular reduction in temperature, thus affording a correspondingly regular control of other correlative functions attendant with the least disturbance to quality and quantity of desirable light hydrocarbons produoed; such practice proving of great value in correcting abnormal rises in temperature.

An incidental object of the invention is to provide for quickly'cooling the entire liquid content of the still in the manner above described to below its point of autoignition, such method in conjunction with simultaneous release through the line from the lower transverse drum which is called the drop-out line proving of immense value in emergency and ordinary shut-downs; the likewise progressively regular reduction in temperature of still and of furnace setting militating against unequal stresses and contractions, thereby adding to life of parts involved. However, material used for the flushing injection may be preheated, as desired, to the approximate temperature of the still contents, so as to cause a minimum disturbance of the normal temperature and pressure conditions within the still.

Another object of the invention is to provide means for quickly replacing substantially the entire body of circulating oil in the still, without shutting down or discontinuing the run, by rapid- 1y charging preheated fresh oil into one part of the still and withdrawing, at substantially the same rate, deteriorated oil containing undesirable constituents from another part of the still whereby the entire degraded contents of the still may be substantially replaced with fresh oil.

I accomplish the primal purpose of continuity or substantial continuity of flow of oil from the still by employing either a single or plurality (preferably two) of perforated inflow and outflow lines within the still, in combination with one or aplurality (preferably two) of charging and withdrawal lines outside the still; discharging continuously where a plurality of inflow and outflow lines inside the still are employed with one or more charging and one or more withdrawal lines outside the still, and discharging substantially continuously where one inflow and outflow within the still is used in connection with one charging and one withdrawal line.

Lines for rejecting material from the still and for forcing material back into the still may be located at any point where tendencies exist for solid material to accumulate in the still. It may be found desirable to enter one or more lines at or near the bottom of the lower transverse drum through which a portion of the still contents may be rejected and fresh material forced back into the still during the run, so as to throw any precipitated materialin the rear and lower drum back into suspension.

Instead of utilizing oil from an exterior source which has been preheated, as a flushing material, the heated contents of the lower drum of the still may be piped to the upper drum or to any other portion of the still in which the flushing apparatus is located; the movement of the oil through such pipe being effected by thermosiphonic action only or such movement may be accelerated by means of a separate pump, propeller, or other mechanical circulatory means. By this means preheated. material of approximately the same temperature as the still contents is available for flushing purposes without the necessity of any separate auxiliary heating means.

While the outflow line or lines may be located at any part of the system, I prefer to locate them at the upper transverse drum as close to the bottom thereof as good practice will allow. the case of one withdrawal line and one or tfiow line, the latter may be fashioned from two substantially equal lengthened perforated nipples issuing from a central T, the assembly extending by an unperforated line passing outside the drum.

If two withdrawal lines are employed, they may be entered at diametrically opposite points of the upper transverse drum, each line extending to approximately the center thereof, or two parallel lines, located adjacent to the bottom of the drum a few inches apart and fashioned similarly to the single line may be employed. In each case the perforated sections are perforated with a sufhcient number of holes or slots to permit of maximum discharge, the diameter of such holes or slots progressively increasing with recedence from inlet of pipe, and their areas being inversely proportional to speed of liquid flow. The single outflow line may be connected by means of a three-way valve to charging stock line and low pressure vapor separator, and the two outflow lines may be similarly connected by means of a four-way valve; or a plurality of charging and withdrawal lines fitted with proper control valves may be used as desired.

With the single line, flow of oil from the still occurs for an uninterrupted cycle of hours dependent on rate of cracking, nature of charging stock and amount of adsorbents employed. When a slackening of volume of the oil flowing from the still is apparent, and cannot be corrected by other means, the flow of oil from the still is shut off and a suitable quantity of virgin or other stock is pumped (at charging pressure) through the line into the still, this having the effect of either'mechanically dislodging the accumulaion of heavy'material surrounding the perforated discharge pipe, or dissolving the bitumens cementing the agglomerate, allowing a certain portion thereof to return to solution and the remainder into suspension and general- 1y clearing the immediate space around the perforated nipples, so that the withdrawal of oil at full volume is again possible, upon shutting off charging stock flow and opening proper valves. Since the rejected material is discharged with the flow of the circulatory stream in the still, the corrective material forced through the flushed line is in countercurrent to the flow in the still and thus is most effective in forcing any precipitated material into suspension.

In the case of two outflow lines in combination with a four-way valve and one charging and one withdrawal line, charging or other stock may be continuously pumped into the still through the one line, in quantity just sufficient to maintain same and the immediately adjacent space to perforated sections thereof free from ac cumulates or agglomerates; alternately changing to the other at suitable periods depending on the previously enumerated conditions.

Inasmuch as the withdrawal cycle is usually a matter of eight to twelve hours upwards against a few minutes interruption in case of the single line and an even shorter period of time with two lines, the practical result of such substantially continuous process of withdrawal of oil, practiced simultaneously with the continuous functions of charging, production of vapor and intensive circulation, is the maintenance of a uniform state of concentration of the entire liquid content of the still, accompanied by an equal dispersion of solid material; all tending towards a uniformity of cracking conditions favorable to a maximum production of desirable light hydrocarbons of anti-knock character.

However, the invention is not confined to any particular frequency of flushing operation which may be employed intermittently, periodically or continuously, depending'upon the raw material being cracked.

The invention will be more fully understood by reference to the accompanying drawings, wherein:

Figure 1 illustrates a part side and part sectional elevation of one form of apparatus suitable for carrying out my invention; Figure 2 is a front elevation of the perforated withdrawal line assembly, Figures 3, 4 and 5 being detailed plan views of modifications thereof. Fi ure 6 is a cross-section through a typical hole of the perforated nipples shown in Figures '7 and 8. Figure 9 is a plan view of a longitudinal half of the still showing means for forcing a portion of the heated contents of the lower transverse drum through the flushed line in the front transverse drum.

The hydrocarbon (and adsorbent) to be processed is continually introduced to the system by pump 1, through feed pipe 2, past control valve 3, and check valve 4, to distributing elbow 5, in top of bathe tower where in descending stream it meets the ascending hot cracked desirable light oil vapors which enter the tower from the upper longitudinal drum 7, of till 8, through line 9.

The partially dephlegmated crude gasoline vapors leave baiile tower through line it, past pressure control valve 11, to be further refined; the tower condensate, together with any introduced fresh oil and adsorbent flowing back to upper drum through line 12. The upper longitudinal drum of the still is superimposed over front and rear vertical sluiceways 13 and 13 which are joined to the front and rear transverse drums 14 and 14' respectively; the latter being united by the tube bank 15.

The oil in the system is heate by the furnace l6, and is maintained at a temper attire and under a best suited to obtain the desired objectives in yield and composition of products, any excess of pressure being relieved by safety valve 1'7.

The gauge 18 serves to indicate the level 19 of the still charge, a considerable part of which, ranging from to 65%, in proportion to the stock charged is continuously rejected, or withdrawn in acontinuous or substantially continuous manner; such discharged portion being later partially vaporized in a low pressure vaporizer (not shown) before ultimate rejection from system. Simultaneously with the continuous func tions described above, the entire still charge is continuously maintained in a state of intensive and rapid circulation by the propeller 2O operated by motor 21.

Substantially continuous rejection of the'bulk still contents may be effected through the perforated capped npples 22 and 22' (Fig. 2) located at bottom of upper transverse drum 14, the with drawn oilleaving the drum through line 23, past block valve 24, threeway valve 25, block valve 26, and check valve 27, through line 28, to the pre viously mentioned low pressure vaporizer (not shown) while during the interval of interrupted iiow of oil from the still, charging or other stock above still pressure, is pumped through line 29, past check valve 30 and block valve 31, then through threeway valve block valve 24 and line thence through perforated nipples 22 and 22 into upper transverse drum l4, clearing the nipples and space immediately adjacent thereto of the objectionable polymerides as previously described; the discharge cycle, after a few minutes pumping in, being again allowed to recur by closing valve 31, opening valve 26 and setting three-way valve 25 in proper position.

An alternative method of periodic discharge illustrated in Figure 3 employs the perforated capped nipple 32 or 33. If the nipple 32 is first used, the oil having objectionable polymerides suspended therein passes out of drum 14, past block valve 34, four-way valve 35, block valve 36 and check valve 37, then through line 28 to the previously mentioned low pressure vaporizer (not shown), while in the meantime a minimum quantity of charging or other stock sufficient to obtain the desired objective of an open line and immediately adjacent space thereto, is pumped through line 29, past check valve 38, block valve 39, four-way valve 35 andthrough line 40 and block valve 34' to perforated nipple 33, thus entering upper transverse drum; such action being reversed as occasion demands by the simple manipulation of four-way valve 35 so that degraded oil now passesout through the perforated nipple 33 and charging or other cleansing stock enters throughnipple 32.

Figure 4 shows an alternative arrangement of Figure 3, where erforated outflow lines 32' and 33 replace lines 32 and 33; while Figure 5 illustrates perforated outflow lines 41 and 42, connected to charging stock lines 43 and 44, and withdrawal lines 45 and 46 respectively; If the nipple 41 is first employed as a discharge unit, the degraded oil first flows through open main block valve 4'7, against closed block valve 51, through open block valve 53, past check valve into degraded oil line 45, and thence to vaporizer (not shown). During this cycle, charging stock may be con inuously admitted by line44, past check valve 50, through open block valve 52, against closed block valve 54, thence through open main block valve 48, into nipple 42, discharging into drum 14 in quantity suflicient to maintain the desired objective of an open line and immediately adjacent space thereto.

If the flow of reject issuing from nipple 41 shows signs of diminishing, admission of charge ing stock entering through nipple 42 is shut off by closing block valve 52, and degraded oil is now allowed to discharge by the nipple 42, through a mainblock valve 48, against the now closed block valve 52, and out through open block valve 54 past check valve 56, through withdrawal line 46 to vaporizer, and only after such discharge is established through nipple 42, is the diminished flow through nipple 41 stopped by closing block valve 53; bus ei fecting by overlapping increments a continuous flow of degraded oil from the drum.

When the discharge through nipple 41 is shut 01?, the latter may now be cleared by introducing charging stock by line 43, past check valve 49, through open block valve 51, and flowing against closed block valve 53, enter drum through main block valve 47 and nipple 41 in a manner before described; such cycles being reversed as occasion demand.

Figure '7 shows .an enlarged detail of a typical perforated nipple 57, with cap 58 and drilled with ho cs 59- of progressively increasing diameters with recedcnce from main outlet, their areas be ing further inversely proportional to discharge flow. Nipple 57 is also shown in Figure 8 in enlarged detail with slots 60 fashioned similarly to the holes 59. The nipples 57 illustrated in Figs. 7 and 8 are enlarged detail view of elements 22,

22'; 32, 33; .32, 33; and 41, 42. A cross section through a typical hole showing the upper and. lower edges rounded is also illustrated in Figure 6, the rounded edgesacting as a deterrent to clogging by solid bodies or agglomerates.

Figure 9 shows an alternative means for effecting the flushing operation by utilizing a portion of the heated contents from the lower drrun as flushing material. A portion of the heated contents of the still passes out of the rear drum 14' through line 62 past block valve 63, into line 64 past check valve 72, through three-way valve 68 into line 65, past block valve 66 into the front drum 14, block valve '70 being closed. A pump or other mechanical circulatory means 67 may be placed in line 64, if desired to increase the speed of circulation. Line 62 enters the rear transverse drum 14 at a point preferably above the bottom thereof where the oil is clear and suitable for flushing purposes. For the degraded oil to flow out of line 65, three-way valve 68 is set in proper position, block valves 66 and '70 being open, and the degraded oil flows off through line 74.

In emergency or regular shut-downs, cooling oil (charging stock) is introduced through the perforated nipples 22 and 22, 32 and 33 and 32 and 33', or 41 and 42, according to the adaptation installed; the entire contents of the still being maintained in rapid circulation in the mean time by the propeller 20, the still contents gradually drawn off through the dropout line 61 shown in Figure 1, until the still and liquid contents are cool enough to be completely pumped without danger to the former by reason of absorption of radiant heat from the furnace setting.

Provision is made for quick replacement of substantially the entire still contents by rapidly charging preheated fresh oil. into one part of the still and withdrawing oil at substantially the same rate from another part until the original body of oil in the still is substantially withdrawn and replaced by suitable preheated charging stock. This method of operation is advantageous in avoiding shutting down of the still because of deterioration of still contents. Instead of employing separate means for charging and withdrawing the oil to rapidly replace the still contents, the preheated fresh charging stock may be rapidly fed through the feed pipe 2 by fully opening valve 3, the oil being drawn off through the withdrawal line 23 in the front drum at substantially the same rate as fresh oil is being charged into the still through pipe 2. By this rapid flushing of suitable preheated charging stock through the still, the heavy ends, carbon and other undesirable constituents are forced out of the still and the degraded circulatory stream is at the same time replaced by a body of suitable charging stock preheated to the temperature of the still contents, thus preventing interruption of the cracking process.

My invention is not restricted to any definite degree of periodicity nor to the apparatus shown and described and what I claim as new and desire to secure by Letters Patent is:

1. In an oil cracking process for the production of gasoline and other hydrocarbon oil from heavier hydrocarbon oil in which a portion of said heavier hydrocarbon oil undergoing cracking in an enlarged cracking zone is normally withdrawn through one of a plurality of outlets, the steps of simultaneously withdrawing a portion of said heavier hydrocarbon oil undergoing cracking through another of said outlets as the flow diminishes in the first-mentioned outlet because of clogging, subsequently interrupting the normal withdrawal of oil through said first-mentioned outlet, and during such interruption forcing hydrocarbon oil through said first-mentioned outlet in reverse flow to the oil normally withdrawn therethrough to remove accumulated solid reaction products from said first-mentioned outlet.

2. A process for obtaining gasoline and other hydrocarbon oil by cracking heavier hydrocarbon oil in a pressure still which comprises the steps of subjecting the heavier hydrocarbon oil to a cracking temperature under pressure in a cracking zone, continuously taking off vapors therefrom, continuously supplying additional heavier hydrocarbon oil thereto, continuously withdrawing during said process a stream of oil from the oil undergoing cracking from a part of said cracking zone through one of a plurality of outlets, at intervals during said process alternating such continuous withdrawal of oil to another one of said plurality of outlets, during such alternation withdrawing a second stream of the oil undergoing cracking through an outlet from another part of said cracking zone and forcing said last mentioned stream of withdrawn oil into the oil undergoing cracking in said cracking zone in reverse flow through that one of said plurality of outlets from which the withdrawal of oil is alternated therefrom.

3. In a cracking process for the production of gasoline and other hydrocarbon oil from heavier hydrocarbon oil in which a portion or the heavier hydrocarbon oil undergoing cracking is continuously withdrawn during said process through one of a plurality of outlets in one part of a cracking zone, the steps of withdrawing said oil in a stream at intervals through each of the several outlets successively, withdrawing another stream of said oil from another part of said cracking zone and forcing said last mentioned stream of oil in reverse flow through one of said plurality of outlets during a time when the continuous Withdrawal of oil from said cracking zone is efiected through another one of said plurality of outlets.

4. In an oil cracking apparatus, a drum, two perforated nipples extending within and near the bottom of said drum and interchangeably connected to an oil withdrawal and an oil supply line outside said drum, means in said lines for directing the flow of oil from sad drum through one of said nipples and for introducing oil to said drum through the other of said nipples, and means in said lines for reversing said flows of oil.

5. In an oil pressure cracking still containing a body of hydrocarbon oil, means for heating said mass of oil to a cracking temperature in a cracking zone, a plurality of outlets in one part of said cracking zone for continuously withdrawing a portion of the oil so heated, means for alternating the withdrawal of said oil through said outlets, an outlet in another part of said cracking zone for withdrawing hot oil at a cracking temperature and means for forcingsaid hot oil into the cracking zone through each of said plurality of outlets in reverse flow to the oil normally withdrawn therethrough when the withdrawal of oil is alternated therefrom.

NORMAN H. RANSTEAD. 

